Episodic cardiac symptoms, such as arrhythmia, are triggered by a wide variety of events including stress. In order for physicians to effectively diagnose the cause of the attack, they must analyze the particular pattern of the heartbeat irregularity. Electrocardiographic data is commonly used in such an analysis. Unfortunately, most arrhythmias are spontaneous and unpredictable, making detection nearly impossible while at the physician's office.
Portable electrocardiogram monitoring and recording devices for use by persons in outpatient environments have long been known. These devices include those which can be conveniently clipped on to a user's belt for wear throughout his daily routine. With the unit constantly in place, the user can simply press a button to signal the onset of an arrhythmia attack, whereby the unit begins recording the user's ECG data.
Typically, this type of portable unit is equipped with a sufficient amount of internal memory to record several minutes of ECG data. The unit can then be taken into the physician's office where inspection can be made of the electrocardiogram pattern recorded during the arrhythmia episode. Recent ECG recording devices have been equipped with modem interfaces to relieve the user of the burden of traveling to the physician's office. Instead, the modem interface permits the ECG data to be transmitted to the physician's office over a standard telephone line.
While these devices have provided for the effective capture and transmission of ECG data from outpatient environments to a physician's office, further improvements and efficiencies can be achieved. A shortcoming in having a modem transfer the ECG data to the physician's office is that a computer or a transtelephonic receiver must be dedicated at the physician's office to monitor the receiving modem for incoming transmissions. This imposes a significant cost on the office, as computer systems or transtelephonic receivers typically cost several thousand dollars. With a dedicated computer, there is the additional inconvenience that the physician is required to examine the data while on the computer or that someone in the physician's office is required to attend the computer and direct the incoming ECG data to a printer for later inspection by the physician.
In recent years, low-cost facsimile machines have been incorporated into virtually all business offices. Since most physicians' offices are presently equipped with facsimile machines, transmission of ECG data directly to such a machine would provide a substantial cost savings by eliminating the need for a dedicated computer. Furthermore, facsimile devices automatically provide a print-out that the physician may inspect at his convenience. It is, therefore, desired to have a portable device that can receive ECG data from a recorder, convert this data into facsimile format, and transmit the data over a standard phone line to a remote facsimile machine.